This program supports research training at the post-doctoral level in cancer biology, radiation biology, and radiological physics relevant to therapeutic radiology. The training program is of two years duration. The program is open to individuals who hold the Ph.D. degree in one of the basic biological sciences, biochemistry, molecular biology, cell biology, molecular genetics, radiation biology, or in physics or related sciences who wish to pursue cancer-related studies, particularly as applied to therapeutic radiology. The program is also open to individuals who hold the M.D. degree who wish to pursue careers in combining laboratory and clinical research in these same areas. The program takes advantage of the extensive laboratory and clinical research activity in the Department of Therapeutic Radiology, and in this revised application it has been expanded to include trainers in other departments who have interests relevant to radiobiology. Other key elements of this revised application are enhancement of the training environment by major renovations to the research space in the Department of Therapeutic Radiology (supported by both Yale University and the NIH) and expansion of the training opportunities by new faculty recruitments in radiobiology-related fields. The program includes required courses in radiobiology, radiological physics, and in biomedical ethics. Conferences, seminars and workshops cover a range of basic science and clinical topics designed to provide exposure not only to radiobiology, cancer biology, and radiation physics, but also to cancer as a disease. In this amended application, a new panel of faculty advisors has been set up to assist the program director and the training faculty in the selection of trainees and their assignment to research groups, as well as to provide trainee mentoring and supervision. Trainees devote more than 90% of their time to specific long-term research projects and interact with a wide variety of other biomedical science research programs throughout Yale University and the Yale Comprehensive Cancer Center.